[CR] Adding a brazed derailleur hanger: Valid option or heresy?

(Example: Framebuilders:Cecil Behringer)

Date: Thu, 15 Jul 2010 07:55:45 -0700 (PDT)
From: "Thomas Adams" <thomasthomasa@yahoo.com>
To: classicrendezvous@bikelist.org
Subject: [CR] Adding a brazed derailleur hanger: Valid option or heresy?

Dear List:

I'm idly daydreaming on the new frame that's coming, a late 40s Hobbes with 115 rear end and no provision for a rear derailleur.  What would be the best way to fix the bike up for multi speeds?  Frame is probably going to get resprayed after initial test riding.

Of course there are a range of options, from riding it fixed (needs someone fitter than me given the hilly terrain here), multi speed internal hub (is there a modern hub that fits down this narrow?), a separate hanger fitted between the derailleur and drop out, or trying to replace the rear drop out with a modern one.  The last option is a bit too far out for me, and might not be practicable with the skinny stays.

But I was wondering how common was it during the 60's and 70's for someone when renovating a frame to have a derailleur hanger brazed onto the existing drop out?  I had one frame so modified, and it seemed to work fine.  Was this a common practice back in the 60's when derailleurs were on the rise?  Any thoughts either pro or con, practical or philosophical?  Would this be a tricky bit of work for a modern frame builder who maybe has never done this work before?  What says the list? 

Option B is the separate hanger, of which I have several lying around and which are reasonably available from several sources, so lack of hardware isn't the problem.  In fact I've got two old frames (the Algurn and the Holdsworth Sirroco) set up this way, so I've aready proved whatever would be proved by preserving the original drops.  Just wondering if I can do something different this time.  

Option C might be a multi speed internally geared rear hub, but most modern ones are 130mm or bigger.  The 8 speed Sturney fits down this narrow, but seems geared for smaller wheels, requiring a massive rear cog and a teeny front ring to get some useful ratios on a 700c wheel.  I am planning on spreading the rear to 120mm, but I don't want to go any further than that.  A three speed rear probably isn't suitable, given the hills here and my feeble fitness level.

What say you, list?

Tom Adams
Manhattan, KS, USA